1. Field of the Invention
The invention relates to an underwater clamp-type release apparatus, and more particularly to an electrically controlled underwater clamp-type release apparatus.
2. Description of Related Art
As referring to a prior art of the U.S. Pat. No. 5,022,013, FIG. 1 and FIG. 2 are partial cross-sectional views of an underwater clamp-type release apparatus showing in closed state and open state respectively. As shown in FIG. 1 and FIG. 2, a release apparatus 24 has a clamp 36 that is positioned between two plates 56 and is pivotally connected at a pin 38. The clamp 36 has a pair of clamp arms 62. Each of the clamp arms has one end including a curve jaw 66, a concave part 68, and a clamped surface 70 for clamping and holding a working piece 22. The other end of the clamp arm is contained in a coupling 48 (as will be depicted later) when the clamp arms are in closed state.
When a motor 50 is started, it drives a gear train having gear 74 and lead screw 76. Consequently, the gear train makes the central shaft 58 of the release apparatus 24 push a plunger 46 to slide back and forth in a cylinder 44 wherein the plunger 46 has a plurality of water-tight-seal 72. A coupling 48 having a recess 50 at the bottom surface thereof is fixed to the lower end of the central shaft 46. A bottom plate having a recess 60 facing downward is attached to an end cap 34 as shown in FIG. 1. When the clamp arms 62 are in closed state, the top ends of the clamp arms 62 are contained in the recess 50 of the coupling 48. But when central shaft 58 together with the coupling 48 is driven to move up, the clamp arms 62 are broken away from the coupling 48 that in sequence cause the clamp 36 to open. Consequently, the clamp arms 62 are changed from the closed state to an open state to release a working piece 22 as shown in FIG. 2.
Prior art""s technology in the U.S. Pat. No. 5,022,013 as described above makes use of the motor 50 that can generate linear displacement at the output end. The motor 50 is coupled with a gear 74 that meshes and drives a lead screw 75, and in sequence, makes the coupling 48 at the output end move up and down in order to control the closed and the open states of the clamp 36. Therefore, a displacement space between the coupling 48 and the release apparatus 24 is necessary. But oftentimes, when the coupling 48 of the underwater clamp-type release apparatus 24 is pulled upward and going to be contained in the recess 60, foreign objects such as shell fish in the sea may be clogged in the recess 60. This will cause the coupling 48 to fail to be contained in the recess 60 under the end cap 34. Consequently, the release apparatus 24 is unable to open the clamp arms 62, and eventually, to release the working piece 22.
Moreover, the opening of the prior art""s clamp arms 62 relies on the motor 50 to drive the transmission of the meshing gear train 74, 76 to make the coupling 48 (equivalent to a rotationally controlled block 140 as will be depicted later in the present invention) perform linear movement. When the coupling 48 touches the top ends 64 of the clamp arms 62, the clamp arms 62 clamp the working piece 22. But when the coupling 48 moves up to separate from the top ends 64 of the clamp arms 62, the clamp 36 is released to open the clamp arms 62. Since this kind of gear-and-lead screw meshing movement is very slow, the efficiency of the releasing work for the working piece 24 is significantly affected.
What is more, the overall structure, particularly the transmission mechanism 74 and 76 of the release apparatus 24 of the prior art is rather complicated. As a result, the required parts are a lot, thereby, not only it is inconvenient to operate but the maintenance is not easy and costly, consequently, the manufacturing cost and sale price are rather high.
The invention is directed to an improved underwater clamp-type release apparatus that can smoothly and efficiently complete a working piece releasing work without being interfered because of the clogging at the release mechanism of the foreign objects such as shellfish in bodies of water.
The invention is also directed to an improved underwater clamp-type release apparatus employing a xe2x80x9crotationally controlled blockxe2x80x9d to be turned only a 90-degree angle to be able to release a working piece. A microswitch is also employed to position the 90-degree turned xe2x80x9crotationally controlled blockxe2x80x9d and to switch off the power supply. This is not only positive in action, convenient in operation, but is also able to improve the working efficiency.
The invention is further directed to an improved underwater clamp-type release apparatus that is simple in design, facilitative in operation, and low cost in manufacturing.
The underwater clamp-type release apparatus of the invention has a main body and a release mechanism. The main body includes a housing, a motor stand, and a speed reducing gear motor while the release mechanism includes a base plate, a pair of clamp frames, a clamp, and a xe2x80x9crotationally controlled blockxe2x80x9d. The clamp is positioned between the two clamp frames and is pivotally connected to the clamp frames at a pin installed through the holes at the clamp and the clamp frames. The top end of the clamp has a concave part for clamping and holding the working piece. The xe2x80x9crotationally controlled blockxe2x80x9d includes a bottom block, and an annular wall wherein the size of the inner diameter of the annular wall can just fit to contain the second end of the pair of the clamp arms when they are closed, and wherein the annular wall includes two openings opposite each other (180-degree apart), and the total width of the second end of the clamp arms when they are closed can make them just pass the openings when the two clamp arms are tending to open. Therefore, when the xe2x80x9crotationally controlled blockxe2x80x9d is controlled to turn an angle of 90-degree, two clamp arms are aligned with the openings at the xe2x80x9crotationally controlled blockxe2x80x9d to be opened, and the working piece is released.
When an electrically controlled type of operation is employed for the release apparatus, a cable is passed through the penetrating hole at the bottom of the housing in the main body, and after the wiring work for installing switches and various devices is completed, the release apparatus is thrown into the sea, power is switched on to actuate the xe2x80x9cspeed reducing gear motorxe2x80x9d, and until the apparatus is sunk into a predetermined set depth, the rotationally controlled block is turned an angle of 90xc2x0. And the clamp arms are aligned with the openings to be released from the xe2x80x9crotationally controlled blockxe2x80x9d, consequently, the working piece is released, in the meantime, the microswitch is propped up by the cam to position the camshaft and to switch off the power.